Comparison of soil organic carbon stocks predicted using visible and near infrared reflectance (VNIR) spectra acquired in situ vs. on sieved dried samples: Synthesis of different studies
2021
Cambou, Aurélie | Allory, Victor | Cardinael, Rémi | Vieira, Lola Carvalho | Barthès, Bernard | Ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes (UMR Eco&Sols) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro ; Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro) | Laboratoire Sols et Environnement (LSE) ; Université de Lorraine (UL)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Agroécologie et intensification durables des cultures annuelles (UPR AIDA) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | Département Performances des systèmes de production et de transformation tropicaux (Cirad-PERSYST) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | University of Zimbabwe (UZ) | GRIPSOL project (Agroforestry for soil protection; contract 1260C0042) financed by ADEME (French agency for ecological transition) through the call for proposals REACCTIF (Research on climate change mitigation in agriculture and forestry) | INCA project (In-field spectroscopy for carbon accounting; contract 1060C0093) supported by the GESSOL program of the French Ministry of ecology, sustainable development and energy, and was funded by ADEME. | SUPRA project (Sols urbains et projets d'aménagement; contract 1772C0021) financed by ADEME, | Région Pays de la Loire, France.
International audience
اظهر المزيد [+] اقل [-]إنجليزي. There is increasing demand for data on soil organic carbon (SOC) stock (SSOC; kgC m−2), but the acquisition of such data, which relies on the determination of volumetric SOC content (SOCv; gC dm−3), is often tedious or complex. Visible and near infrared reflectance spectroscopy (VNIRS) has proven useful for soil characterization, but has rarely been used for direct prediction of SOCv. The objectives of this work were: (i) to compare SOCv predictions using VNIR spectra collected in situ vs. on 2-mm sieved air-dried soil (laboratory conditions), on three sample sets separately (with in situ spectra collected differently for each set); and (ii) to assess SOCv prediction in independent validation using laboratory spectra from all sets.Predictions of SOCv were more accurate using laboratory than in situ spectra for two sets, but not for the third set, where coarse particles content was rather high and variable. Considering the total set of laboratory spectra, predictions in independent validation (leave-one-site-out) yielded accurate SOCv and SSOC predictions (standard errors of prediction were 1.9 gC dm−3 and 0.36 kgC m−2 at 0–30 cm depth, respectively). This result was achieved using local partial least squares regression (PLSR), based on spectral neighbors, which noticeably outperformed global PLSR (which uses all calibration samples equally), as often reported when using large soil spectral libraries for independent validation.Finally, this work demonstrated that SSOC could be quantified accurately using a VNIRS library built on archive soil samples, which offers important perspectives for SSOC accounting.
اظهر المزيد [+] اقل [-]المعلومات البيبليوغرافية
تم تزويد هذا السجل من قبل Institut national de la recherche agronomique